1. Field
The present invention relates a method for using retinoid antagonists, such as retinoids with selective Retinoic Acid Receptor ("RAR") antagonistic activity, Retinoid X Receptor ("RXR") antagonistic activity or mixed RAR-RXR antagonistic activity, to treat T-helper cell type 2 ("Th2")-mediated immune diseases. Th2-mediated immune diseases include immunoglobulin E ("IgE")-mediated allergic diseases. The present invention also relates to using retinoid antagonists to prepare medicaments for treating Th2-mediated immune diseases.
2. Description
Retinoids are a class of compounds structurally related to vitamin A and include natural and synthetic compounds. Retinoids are clinically useful in the treating dermatological and oncological diseases.
Retinoid activity is thought to be mediated by the nuclear retinoid receptors RAR.alpha., .beta., .gamma. and RX.alpha., .beta., .gamma., belonging to the superfamily of steroid, thyroid hormone, vitamin D, peroxisome proliferator-activated receptors [Pfahl et al., Vitamins and Hormones, 49: 327-382 (1994)]. Retinoids with receptor agonistic activity bind to and activate receptors, whereas retinoids with receptor antagonistic activity bind to receptors but do not activate them.
Experimentally, retinoids with retinoid receptor agonistic activity have been shown to be active in model systems for treating dermatological and oncological diseases and in models for treating immunological diseases. Retinoids with retinoid receptor agonistic activity have been shown active in treating adjuvant arthritis [Brinckerhoff et al., Science, 221: 756-758 (1983)] and experimental allergic encephalomyelitis [Massacesi et al., J. Clin. Invest., 88: 1331-1337 (1991); Racke et al., J. Immunol., 154, 450-458 (1995)], animal models for rheumatoid arthritis and multiple sclerosis, respectively. Both diseases are considered to belong to Th1-mediated immune diseases.
Experimentally, retinoids with retinoid receptor antagonistic activity (retinoid antagonists) have been shown effective in counteracting many properties of retinoids with retinoid receptor agonistic activity (retinoid agonists), such as inhibiting cell proliferation, inducing cell differentiation, inducing apoptosis and inhibiting angiogenesis [Bollag et al., Int. J. Cancer, 70: 470-472 (1997)]. Retinoid antagonists also suppress toxic side effects of retinoid agonists, such as the signs and symptoms of the hypervitaminosis A syndrome and teratogenesis [Standeven et al., Toxicol. Appl. Pharmacol., 138: 169-175 (1996); Eckhardt and Schmitt, Toxicol. Letters, 70: 299-308 (1994)]. Therefore, they may be useful clinically in preventing or treating adverse events caused by retinoid agonists.
Retinoid antagonists have been proposed for clinical use in the prevention and treatment of retinoid-induced toxicity and side effects, particularly of the so-called hypervitaminosis A syndrome. Retinoid antagonists have also been proposed to be used in combination with retinoid receptor agonists or other nuclear receptor agonists for preventing and treating preneoplastic or neoplastic lesions, vitreo-retinopathy, and retinal detachment. In addition, retinoid antagonists may be useful as single agents, based on their anti-proliferative effect, for treatment of certain neoplasms insensitive to retinoid receptor agonists [WO 97/09297].
The subject invention provides for the first time a method for using retinoid antagonists in the treatment of Th2-mediated immune diseases, such as IgE-mediated allergic diseases and diseases mediated by the Th2-related cytokines.